Remove more feature in product mode

runtime/vm/deopt_instructions.h

Index: runtime/vm/deopt_instructions.h
diff --git a/runtime/vm/deopt_instructions.h b/runtime/vm/deopt_instructions.h
index 3dd538f311a81b94a137ebdf1f53aabc69b4a03a..229a0aaec1c985cd2221ef60bf7a3624408b91f8 100644
--- a/runtime/vm/deopt_instructions.h
+++ b/runtime/vm/deopt_instructions.h
@@ -485,7 +485,10 @@ class DeoptInfoBuilder : public ValueObject {
   intptr_t CalculateStackIndex(const Location& source_loc) const;
 
   intptr_t FrameSize() const {
-    return instructions_.length() - frame_start_;
+    ASSERT(frame_start_ != -1);
+    const intptr_t frame_size = instructions_.length() - frame_start_;
+    ASSERT(frame_size >= 0);
+    return frame_size;
   }
 
   void AddConstant(const Object& obj, intptr_t dest_index);